January: Seasonal Temps To End The Month

[srainhoutx]

The 12Z GFS is suggesting a very potent Winter Storm with both severe and wintry elements as the 500mb low deepens across Texas and meandering ENE. The GFS also is suggesting a rather deep surface Coastal Low develops and heads ENE across SE TX into SW LA providing for heavy storms and training potentially flooding rainfall over parts of Central/East Texas into Louisiana. As the upper low strengthens, wrap around moisture of the wintry variety breaks out N of the cold core low across the Panhandle and the Red River Valley possibly into Oklahoma.

Hour 84:

01052013 12Z GFS f84.gif

Hour 90:

01052013 12Z GFS f90.gif

Hour 96:

01052013 12Z GFS f96.gif

Hour 102:

01052013 12Z GFS f102.gif

Hour 108:

01052013 12Z GFS f108.gif

Hour 114:

01052013 12Z GFS f114.gif

[srainhoutx]

I want to mention briefly since there is a lot of chatter concerning the 'colder' air that the models are suggesting near the mid January time frame. The Operational GFS is suggesting a full latitude trough with a potent Winter Storm near the 12th, +/- a day or two developing in the Southern Plains. The EPO is suggested by most all of the guidance (operational and ensembles) to become strongly negative as well as a tanking AO. Heights build across Alaska setting the stage for a very active, stormy and chilly weather pattern for areas W of the Appalachian Mountains.

01052013 12Z GFS 12zgfs500mbHeightAnomalyNA276.gif

01052013 12Z GFS 12zgfs850mbTAnomalyNA288.gif

[sambucol]

I want to mention briefly since there is a lot of chatter concerning the 'colder' air that the models are suggesting near the mid January time frame. The Operational GFS is suggesting a full latitude trough with a potent Winter Storm near the 12th, +/- a day or two developing in the Southern Plains. The EPO is suggested by most all of the guidance (operational and ensembles) to become strongly negative as well as a tanking AO. Heights build across Alaska setting the stage for a very active, stormy and chilly weather pattern for areas W of the Appalachian Mountains.

What does that mean for our area? Snow and ice? Thanks.

[srainhoutx]

I want to mention briefly since there is a lot of chatter concerning the 'colder' air that the models are suggesting near the mid January time frame. The Operational GFS is suggesting a full latitude trough with a potent Winter Storm near the 12th, +/- a day or two developing in the Southern Plains. The EPO is suggested by most all of the guidance (operational and ensembles) to become strongly negative as well as a tanking AO. Heights build across Alaska setting the stage for a very active, stormy and chilly weather pattern for areas W of the Appalachian Mountains.

What does that mean for our area? Snow and ice? Thanks.

It is way too soon to speculate on what it could bring to our Region. That said one thing that I am noticing is that the sub tropical jet appears to remain noisy and the storm track raises an eyebrow for the winter weather lover for much of our Region. Stay Tuned!

[srainhoutx]

A nice visible shot of the snow cover across W Texas, New Mexico, down S into Northern Mexico and across the Plains as well of the Southern Rockies and the front range this afternoon.

[srainhoutx]

HPC Model Diagnostic Discussion concerning the storm next week:

...SRN STREAM SHRTWV TROF AND DEVELOPING CLSD LOW OVER THE
SOUTHWEST...

PREFERENCE: 12Z ECMWF/00Z ECENS MEAN BLEND
CONFIDENCE: ABOVE AVERAGE

THE 12Z NAM ALONG WITH THE 12Z GFS...12Z UKMET AND 12Z GEM GLOBAL
CONTINUE TO TREND TWD A ECMWF/ECENS MEAN LED CONSENSUS SOLN WITH A
DEEP CLSD LOW DIGGING SEWD ACRS CA AND INTO THE SOUTHWEST U.S. BY
LATE SUN...AND THEN SLOWLY ADVANCING DOWN INTO NRN MEXICO WEST OF
THE BIG BEND OF TX BY LATE TUE. THE ECMWF AND TO A LESSER EXTENT
THE UKMET HAVE BEEN VERY CONSISTENT WHEN COMPARED TO THE
GFS/NAM/GEM GLOBAL SOLNS IN HANDLING THIS SRN STREAM ENERGY WITHIN
A LARGER SCALE SPLIT FLOW REGIME. WILL FAVOR A ECMWF/ECENS MEAN
BLEND BASED ON THEIR EXCELLENT RUN TO RUN CONTINUITY.

[srainhoutx]

I want to mention briefly since there is a lot of chatter concerning the 'colder' air that the models are suggesting near the mid January time frame. The Operational GFS is suggesting a full latitude trough with a potent Winter Storm near the 12th, +/- a day or two developing in the Southern Plains. The EPO is suggested by most all of the guidance (operational and ensembles) to become strongly negative as well as a tanking AO. Heights build across Alaska setting the stage for a very active, stormy and chilly weather pattern for areas W of the Appalachian Mountains.

What does that mean for our area? Snow and ice? Thanks.

It is way too soon to speculate on what it could bring to our Region. That said one thing that I am noticing is that the sub tropical jet appears to remain noisy and the storm track raises an eyebrow for the winter weather lover for much of our Region. Stay Tuned!

To add to the above, the 12Z GEFS (GFS Ensembles) and the OP Euro paint a very impressive pattern developing around mid January.

01052013 12Z GEFS 12zgfsensembles500mbHeightAnomalyNH216.gif

01052013 12Z Euro 12zeuro500mbHeightAnomalyNH216.gif

[Ptarmigan]

I am hearing if the forecast holds up, it could be similar to January 1985 freeze. The 1985 freezes occurred in La Nina.

http://www.cpc.ncep.noaa.gov/products/a ... ears.shtml

[nuby3]

January 12-13, 1985 Snowfall above four inches fell over a large area of southwest and south central Texas, generally southwest of a line from Midland to Austin and north of a line from Eagle Pass to Gonzales. Between 8-14 inches fell from the Hill Country to San Antonio and as far south as Eagle Pass.

got this from a nws historical archive thing. pretty interesting, seeing as how a similarity to the 1985 event has been mentioned

[TexasBreeze]

It will be interesting to see if it actually happens, being only 2 wks away....

[sambucol]

It will be interesting to see if it actually happens, being only 2 wks away....

When is this cold supposed to be in SE Texas if it happens? Pipe busting cold?

[Ptarmigan]

It is way too soon to speculate on what it could bring to our Region. That said one thing that I am noticing is that the sub tropical jet appears to remain noisy and the storm track raises an eyebrow for the winter weather lover for much of our Region. Stay Tuned!

The upper ridge over Alaska indicates positive PNA, while upper level ridge ovet Greenland indicate negative NAO. This could bring cold air down to America.

[jasons2k]

I've had .69" over the last two days - so I'm happy with that.

I concur with Ed on the bitter cold. The winter two years ago killed 3 out of 4 of my majesty palms, and they were all wrapped with two propane heaters going in my back yard. Granted, these are barely zone 9B palms so I was really pushing it, but I inherited them from the previous homeowner and hated to see them go. I'd hate to see, for instance, all the date palms at the Portofino Center in Shenandoah all get zapped. Those palms really "make" the shopping center. People who weren't here in the 1980's may not know that Houston and even the RGV looked much different for several years after 1983 & 1989.

[Paul Robison]

Did someone miss this part of the statement from SPC?

WHILE STRONG MID LEVEL FLOW SHOULD ROTATE THROUGH THE
BASE OF THE TROUGH INTO EAST TX AT SOME POINT IT/S NOT ENTIRELY
CLEAR WHEN THIS WILL OCCUR. ADDITIONALLY...THE PROSPECT FOR
MEANINGFUL DESTABILIZATION INLAND MAY BE IMPEDED BY SUBSTANTIAL
PRECIPITATION WITHIN THE WARM CONVEYOR.

Now, as far as Houston is concerned, could the substantial precipitation within the warm conveyor make it difficult for any storms Tuesday/Wednesday from becoming horrendously severe?
BTW: Is this thing a dead ringer for hurricane Ike, or what?

[Andrew]

Euro and CMC seem to agree with the GFS on the cut off low slowing down around the border of Texas and Mexico with storms rotating around it. Seems like the final line of storms that come through could be the strongest if models are right. How long/ if the low stalls will be key for not only rain totals but severe weather.

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/ecmwfloop.html

[srainhoutx]

The SPC issues a Slight Risk for the Lower Rio Grande Valley and portions of S Central Texas for Tuesday that include the cities of Brownsville, Corpus Christ and San Antonio.

DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0221 AM CST SUN JAN 06 2013

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTH TX...

...TX...

LATEST SHORT-RANGE MODEL GUIDANCE CONTINUES TO SUGGEST UPPER LOW
OVER NRN MEXICO WILL BEGIN TO EJECT EWD DURING THE DAY3 PERIOD AS
MID LEVEL SPEED MAX ROTATES TOWARD THE MIDDLE RIO GRANDE RIVER
VALLEY LATE. IN RESPONSE TO THIS FEATURE IT APPEARS LOW LEVEL
TRAJECTORIES WILL BECOME FAVORABLE FOR NWD ADVANCEMENT OF MARITIME
TROPICAL AIRMASS ACROSS DEEP SOUTH TX/LOWER TX COAST. AS SFC DEW
POINTS RISE INTO THE UPPER 60S THERMODYNAMIC PROFILES SHOULD BECOME
INCREASINGLY FAVORABLE FOR SFC-BASED CONVECTION WITHIN A SHEARED
ENVIRONMENT INCREASINGLY FAVORABLE FOR SUSTAINED ROTATING UPDRAFTS.
AS COASTAL/WARM FRONT ADVANCES INLAND BUOYANCY SHOULD INCREASE SUCH
THAT ISOLATED SUPERCELLS ARE POSSIBLE...BOTH ACROSS THE WARM SECTOR
AND PERHAPS JUST NORTH OF THE FRONT WHERE STRONG LOW-MID LEVEL SHEAR
WILL BE PRESENT. STRENGTHENING LLJ AHEAD OF THE PACIFIC FRONT WILL
ENCOURAGE A SUBSTANTIAL AMOUNT OF CONVECTION/PRECIPITATION ACROSS TX
WITH TSTM ACTIVITY ACROSS CNTRL/NRN TX ELEVATED AND LESS BUOYANT IN
NATURE. ISOLATED TORNADOES MAY OCCUR WITH NEAR-SFC BASED ACTIVITY
AND MARGINALLY SEVERE HAIL MAY ALSO ACCOMPANY THE STRONGEST
CONVECTION. NWD EXTENT OF SEVERE WILL BE LIMITED BY COOLER BOUNDARY
LAYER CONDITIONS ASSOCIATED WITH SUBSTANTIAL PRECIPITATION BENEATH
THE WARM CONVEYOR.

..DARROW.. 01/06/2013

01062013 day3otlk_0830.gif

SPC also issues a Day 4 Severe Threat that includes super cells for Austin, Beaumont, Brownsville, College Station, Corpus Christi, Galveston, Houston and Victoria.

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0313 AM CST SUN JAN 06 2013

VALID 091200Z - 141200Z

...DISCUSSION...
CONSIDERABLE DISCREPANCY BEGINS TO EMERGE DURING THE MEDIUM RANGE
PERIOD REGARDING THE EJECTING UPPER LOW ACROSS TX. THE GFS IS
SUBSTANTIALLY FASTER AND FARTHER NORTH THAN THE ECMWF BY DAY5 WITH A
DEAMPLIFYING SHORT-WAVE OVER SERN ONTARIO AT 11/12Z WHILE THE ECMWF
MAINTAINS A CLOSED LOWER NEAR THE ARKLATEX. FOR THIS REASON EXTREME
UNCERTAINTY REGARDING SEVERE EXISTS BEYOND WEDNESDAY.

DURING THE DAY4 PERIOD THERE IS SUFFICIENT CONFIDENCE REGARDING THE
POTENTIAL FOR STRONG THUNDERSTORM DEVELOPMENT ACROSS THE COASTAL
PLAINS OF TX WHERE AMPLE LOW LEVEL MOISTURE WILL HAVE SPREAD INLAND
PRIOR TO THE ARRIVAL OF STRONG MID LEVEL SPEED MAX AHEAD OF PACIFIC
FRONT. IT APPEARS A SUPERCELL ENVIRONMENT WILL EXIST ACROSS THE
AFOREMENTIONED REGION AND LARGE SCALE FORCING SHOULD SUPPORT TSTM
DEVELOPMENT.

..DARROW.. 01/06/2013

01062013 SPC day48prob.gif

Worrisome to see QPF for areas E of HWY 281 or just W of Austin along the Balcones Escarpment into SE TX in the 4-6 inch range. Training appears likely along and E of the warm front with PW's 2 Standard Deviations+ above normal for the Region. I expect Flash Flood Watches to be hoisted and the HPC has outlined the area for a Slight Risk of Excessive Rainfall for Day 3.

01062013 HPC Excessive Rain 99ewbg.gif

01062013 HPC QPF p120i.gif

[srainhoutx]

I'll also mention the wintry side potential of this potent Storm System. This storm will likely be very dynamic with a closed cold core 5H low that is slow moving. A trowal appears likely across portions of the Panhandle Regions of TX/OK extending WSW into Eastern New Mexico bringing impressive heavy wet snow fall to Roswell/Ruidoso/Carlsbad/Hobbs and possibly into Lubbock as well depending on the eventual storm track and speed. The GFS has been on the progressive side, but has trended toward the slower much stronger Euro solution. As we have seen in the current pattern of the last couple of weeks, the European guidance has been more correct and has slowed the progression of these closed 5H low traversing across Northern Mexico.

[Ounce]

Is there much probability for highs in the low 60's for next Sunday's marathon? Much obliged.

[Portastorm]

Per their morning AFD, EWX is anticipating 2-4 inches of badly needed rain for south central Texas from this next system. Possibly a bit more.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
ISSUED 439 AM CST SUN JAN 6 2013

..INGREDIENTS COMING TOGETHER FOR A MID WEEK HEAVY RAINFALL EVENT
WITH SOME SEVERE STORMS...

DISCUSSION...
A SURGE OF HIGH PRESSURE IS MOVING INTO SOUTH CENTRAL TEXAS THIS
MORNING. AFTER A COLD START WITH TEMPERATURES AT OR BELOW FREEZING
ACROSS A LARGE PART OF OUR AREA...NEARLY SEASONAL TEMPERATURES CAN
BE EXPECTED TODAY. THE SURFACE RIDGE SETTLES OVER OUR AREA TONIGHT
WITH FREEZING TEMPERATURES ACROSS MUCH OF THE HILL COUNTRY TO
ALONG THE ESCARPMENT.

THE SURFACE RIDGE DRIFTS OFF TO THE EAST ON MONDAY AS AN UPPER
LEVEL LOW CURRENTLY MOVING SOUTH ALONG THE CALIFORNIA COAST MOVES
INTO NORTHWESTERN MEXICO INDUCING SURFACE PRESSURE FALLS IN THE
SOUTHERN HIGH PLAINS. MODELS HAVE COME INTO MUCH BETTER AGREEMENT
FOR AT LEAST THE EARLY TO MIDDLE PARTS OF THE UPCOMING WEEK. MOIST
SOUTHEASTERLY WINDS RETURN MONDAY LEADING TO CHANCES OF SHOWERS
MONDAY NIGHT.

THE STRONG UPPER LEVEL LOW WILL MOVE EAST ACROSS NORTHERN MEXICO
TUESDAY TO THE BIG BEND WEDNESDAY MORNING...THEN SLOWLY EAST AND
NORTHEAST ACROSS TEXAS WEDNESDAY INTO THURSDAY. A WARM FRONT LIFTS
NORTH ACROSS EASTERN AREAS TUESDAY INTO TUESDAY NIGHT...THEN AN
INVERTED TROUGH A PACIFIC COLD FRONT TAKE SHAPE AND MOVE EAST
ACROSS OUR AREA LATE TUESDAY NIGHT INTO WEDNESDAY.

STRONG LIFT...UPPER LEVEL DIFFLUENCE AND MOISTURE CONVERGENCE
INDICATE NUMEROUS TO WIDESPREAD SHOWERS AND THUNDERSTORMS TUESDAY
THROUGH WEDNESDAY. HAVE INCREASED POPS FOR TUESDAY NIGHT INTO
WEDNESDAY. CONVECTIVE PARAMETERS INDICATE THE POSSIBILITY OF
STRONG TO SEVERE STORMS ESPECIALLY NEAR AND SOUTH OF THE WARM
FRONT AND ALONG AND EAST OF THE PACIFIC FRONT. THE MAIN THREATS
WILL BE DAMAGING WINDS AND LARGE HAIL...ALTHOUGH CAN NOT RULE OUT
A TORNADO SOUTH OF THE WARM FRONT. PWS RISE TO WELL ABOVE AVERAGE
FOR JANUARY INTO THE 1.3 TO 1.7 INCH RANGE. THE HIGHER VALUES ARE
NEAR THE MAXIMUM OBSERVED VALUES FOR JANUARY. THUS...THESE
PWS...THE SPEED OF THE SYSTEM AND TRAINING OF SHOWERS AND
THUNDERSTORMS SUGGEST HEAVY RAINFALL. EXPECT RAINFALL TOTALS OF 2
TO 4 INCHES GENERALLY ALONG AND EAST HIGHWAY 281 WITH ISOLATED
TOTALS OF 4 TO 6 INCHES. RAINFALL TOTALS WEST OF HIGHWAY 281 WILL
TAPER OFF TO NEAR 1/2 INCH ALONG THE RIO GRANDE. THE SHOWERS AND
THUNDERSTORMS WILL END FROM SOUTHWEST TO NORTHEAST LATE WEDNESDAY
INTO EARLY THURSDAY AS DRIER AIR WORKS INTO THE SYSTEM.

FAIR WEATHER IS EXPECTED THE REMAINDER OF THURSDAY INTO FRIDAY ON
DRY WESTERLY FLOW. AHEAD OF ANOTHER UPPER LEVEL TROUGH AND SURFACE
COLD FRONT...SOUTHERLY FLOW AND MOISTURE RETURN FOR SATURDAY. THE
SYSTEM MOVES ACROSS NEXT SUNDAY WITH LOW CHANCES OF SHOWERS AND
THUNDERSTORMS SATURDAY NIGHT INTO SUNDAY. THERE IS SOME
DISAGREEMENT WITH THE NEXT WEEKEND SYSTEM. HAVE FAVORED THE SLOWER
ECMWF AND NOGAPS RATHER THAN THE FASTER GFS BASED ON BETTER RECENT
PERFORMANCE OF THE ECMWF.

[srainhoutx]

Is there much probability for highs in the low 60's for next Sunday's marathon? Much obliged.

Right now the GFS is suggesting temps in the 50's and perhaps a cold front passing next Sunday and it could be rather wet with storms across SE TX, Ounce. Keep checking back and we will 'fine tune' the forecast for the Houston Marathon as we get a bit closer and beyond the event expected Tuesday/Wednesday.

01062013 IAH GFS iahgfs.png

06Z GFS:

01062013 06Z GFS f174.gif